Making Database Administration Easier with Freeware

September 12, 2007

Depending on your
environment, working with and between Windows and UNIX can be somewhat
problematic. It seems that no two workplaces are the same when it comes to the
network file system. Two of the more commonly seen problems include not being
able to get a GUI tool (e.g., Oracle Universal Installer) to display and not
being able to have it display at the correct location. There is a freeware tool
to help you work around these problems and make your job of administering
Oracle (and Oracle products) easier.

Common UNIX Environments

Listed below is a list of
environments commonly seen in the workplace. UNIX, in these examples, refers to
Solaris, AIX, HP, Linux and so on (the variants are sometimes referred to as
*NIX).

Case 1 - Physical access
to the UNIX (or database) server

If a smaller server, such as
a SPARC workstation, youre probably in a development shop, so logging onto the
actual server may be as simple as rolling your chair across the office to sign
on. If a larger server, such as those found in a production environment, the
server (or servers) may be located in a computer room. The room may be an
environmentally controlled/temperature regulated/restricted access room, but
the point is, you can go into the room and physically access the server (even
if that means youre pulling out a laptop built in to the rack).

Case 2 - Indirect access to
a specific server

In this environment, your
access or logon to the server is through an application (on your PC) such as
PuTTY. Information about PuTTY can be found in numerous places, and this site is fairly concise and
relevant to our needs.

The information typed into
the Host Name field is the name of the specific server you want to connect
to. You can save the connection information for each server and load them as
needed.

Case 3 - Indirect access
to a specific server via a gateway

What differentiates this
case from the previous one is that you cannot logon directly to a real
server, but first must go through a gateway server (you logon to services,
and once you are authenticated, you can SSH onto your server of interest).

Direct logons are the
easiest when it comes to having a GUI-based application displayed at the
monitor in front of you. It shouldnt be hard to figure out that our number one
GUI-based application of interest here is Oracle Universal Installer.

In general, obtaining or
acquiring command line interface is not a problem. What is a problem, as
evidenced by the roughly 28 million Google hits on Cant open display (and
not counting the seven on MetaLink) is getting a GUI to 1) display and 2)
display to the correct monitor.

X, or The Truth is Out There

If youve ever been frustrated
with X (or X11 or X-Windows), youll definitely enjoy reading chapter 7 of The
UNIX-Haters Handbook. One OpenSSH application in particular can take care
of connecting (via SSH) and displaying GUIs such as OUI, and that application
is Cygwin, a Linux-like environment for
Windows. During the installation of Cygwin, the selection of SSH and X options
give you a quick, easy way to access a server, open an xterm window, and have
GUIs display just like that. After downloading the setup.exe program, the first
several windows shown in the installation process are self-explanatory. The
window you need to go beyond just clicking Next is shown below.

Scroll down to Shells and
select tcsh (expand it and ensure the box is checked). The bash option will
probably work as well, but it may take a few install attempts to get the right
combination for your environment.

Lastly, the other option to
have installed (aside from the defaults) is found by expanding the last
category (X11) and scrolling down to the very bottom. The package of interest
is xterm. Ensure that is selected and click Next to finish the installation
process.

The installation will take a
few minutes (mileage varies based on which mirror site you selected and your
Internet connection). When the installation is finished, start Cygwin and
youll see a shell-like window. This window will look and operate much like
youre on a Linux machine. Type env and you can see how Cygwin translates many
of your Windows settings (e.g., environment variables) into a UNIX-like format.

At this point (assuming
youre in a case 2 environment), enter startx. A new X window will appear, and
from this window, you can logon to the server where you need to run OUI.

The trick here is to add
-X in the ssh call. Enter ssh X oracle@server_name, and supply the password.
Entering xclock at this point should cause the clock GUI to appear. At this
point, if you know you can get an X application to run (xcalc and xeyes are
others), you can get OUI to start (given that all of the system prerequisites
have been met).

Even on your PC, you should
be able to see X applications run.

Notice there was no need to
set the DISPLAY environment variable or use the xhost command. There was no
lets reverse what client and server mean confusion introduced by X-Windows.
Even better, when compared to other tools and a cost of hundreds of dollars
(see Exceed),
the freeware price of Cygwin is hard to beat.

In Closing

You can spend lots of time
trying to get an X-based application to display, again the main reason to run
an X application is to test your ability to run OUI. If nothing seems to work,
not being able to launch OUI is not a show stopper, as the RDBMS and other
products can all be installed using response files. Depending on your
environment, you can still try the established way of using xhost and setting
the DISPLAY environment variable.